Barge loading device



g- 1940' H. c. ELLIOTT BARGE LOADING DEVICE 4 Sheets-Sheet 1 6 r 0$ 33ul-ll 1 Q m W 5% 4 1 4 a 6 :1. m h m: m 1+6 1 J 7 v a a i? w ,M? m

- 2- 0, 1940. H. c. ELLIOTT BARG E LOADING DEVICE 4 Sheets-Sheet 2 FiledMay 16, 1940 7 (Q Maw 216W ATfORNEYS Filed May 16, 1940 I 4 Sheets-Sheet3 INVENTOR. 6 2 ATTORNEY BY WM 6 7 9 1 2 m m w 9 7 do w g- 20, 1940. H.c. ELLIOTT 2,212,064

BARGE LOADING DEVICE Filed May 16,-1940 4 Sheets-Sheet 4 INVENTOR.

W MATTORNEY'J Patented Aug. 20, 1940 PATENTQOFFICE;

BARGE LOADING DEVICE Harry 6. .Elliotar'. Cincinnati, Ohio, assignor QtoThe Mississippi Valley Barge -Line C0mpanya. St. Louis, Mo -acorporation of Delaware;

Application May16,'1940, Serial No. 335,595

12 Claims.

This invention relates to elevators of the type adapted particularlyforhandling'freight. More specifically, the invention relates to a portableelevator suitable foruse in the loading andunloading of barges;

In recent years, unit barges have been used extensively in inlandwaterway transportation; these usually are comprised of a hullprovidinga hold,a deck which is removable in sections,

and a deckhouse, enclosing the hold and the -removable portions of thedeck; The roof "also ismade up of hatches Which'can be lifted from'thedeck house or rolled to uncover sections of it. In

the use of these barges, freight is loaded into the hold through the"deck apertures and additional freight is then loaded within thedeckhouse. Equipment of the general type is disclosed, for

example in the Elliott Patent No. 2,150,763 issued" March 14, l939-and,while the elevators of the present invention are useful for the handlingof freight through the hatchways of seagoingvesselsas well as of barges,the invention is disclosed particularly in relation to the latter typeof equipment.

Heretofore it has been necessary to pass freight by hand into or out ofthe hold of the barge; The operation obviously is a very slow andtedious one, and the costs of barge loading and unloading constitute asubstantial proportion of thetotal cost of transportation; particularlywhen-the shipping is between local points on a river:

The'primary object of the presentdnvention has been to provide aportable elevator for lowering and lifting freight from and to the bargehold; Itisintended that the elevator be arranged tooperate over awellwhich' is provided through the removal of a portion or section ofthe deck of the barge, or through the roof of the barge, as the case maybe.

A further object of the invention has been to provide a portableelevator of this type which embodies a number of safety features whichmake its use both safe and convenient; these features tion with theelevator for bridging the-gap between the platform and the aperture inthe roof or deck through which the freight is being handled; andapparatus for stiffening and rigidifying the frame of the elevatorvwithout. obstructing the, freight handling passageway,

A further object of the inventionis to provide means for holding theelevator, in stationary position after it has been wheeled tolocationrBriefly, the apparatus of the invention comprises a wheeled carriage anda platformor lift, which is arranged to be loweredand hoisted throughthe carriage and supported from it;'

The carriage supports a hoisting or drive mechanism for operating theplatform, and also, in the preferred embodiment is provided with asuperstructure through which the platform .is interconnected 'with* thehoisting mechanism. However, the carriage or chassis for the elevatorlift, also carries collapsible guide members which are arranged todepend from.it,so as to guide the platform. as it. is. lowered to aplane below the carriage wheels, or, in other words, as it is lowereddown into the hold of the barge, when the wheels of the carriage areresting upon the deck.

The collapsible members normally are nested toreside within thesuperstructure of theele-v vator so that they are out of the way when itis being positioned for usage- Thereafter, however, these guide unitsare moved into positions appropriate for them to guide the platform; asit is raised or lowered. In the preferredembodiment the platformincludes members cooperating with the'guide members of the carriage toprevent it from-swinging as it is being operated.

For the control of the elevator upper and lower limit switches, adaptedto control the operating of the hoisting mechanism, are operated byacontrol dog which is driven by a traversing screw rotating insynchronism with the hoisting mechanism. The limit switches arepositioned to control the drive apparatus when the platform reaches itsupper or lower stopping positions.

The apparatus, on the 'whole, is sulficiently compact either to bewheeled into a barge over gangplanks appropriately mounted, or to belowered to the barge by the use of a crane with which most riverterminals are provided. Then, the collapsible guide members are movedinto their extended, or guiding positions andthe elevator is ready to beused upon the provision of electric current, whichcan be supplied fromthe terminal or from 'a towboat.

Various features and advantages of the invention which have not alreadybeen described, are disclosed in the following specification and in thedrawings, which illustrate a preferred embodimerit: of the invention.From the foregoing principle' description of features upon which theinventionis predicated, and from the following detailed description ofthe structure, those skilled in the art readily will comprehend thevarious modifications to which the invention is susceptible.

In the drawings:

Figure 1 is a plan view showing the elevator in position over anaperture in a barge deck.

Figure 2' is a side elevation of the elevator with the platform in theprocess of being lowered or raised.

Figure 3 is a sectional elevation taken on the line 3-3 of Figure 2. Inthis figure the platform is shown in lowered position.

Figure 4 is a fragmentary sectional view taken on the line 4-4 of Figure2 and illustrates a support for the elevator and toggle for operatingit.

Figure 5 is a fragmentary side elevation showing the details ofconstruction of the brow plate.

Figure 6 is a fragmentary elevation showing details of construction'ofthe elevator controller.

Figure 7 is a fragmentary cross sectional view taken on the line 1 -1 ofFigure 6.-

Figure "8 is a fragmentary perspective view showing the arrangement of.guide sheaves for supporting the elevator cable.

I Figure 91s a fragmentary sectional elevation taken on the line 9+9 ofFigure 3 illustrating the construction of a platform bumper.

Figure 10 is asectional view taken on the line Ill-l0 of Figure 2showing details of the elevator drive gear.

"'"lift facilities provided at a river terminal.

Support members indicated generally at l are Figure 11 is asectionalview taken on the line ll|l' of Figure 10 showing'further details of theelevator drive. v

Frame assembly apart from one another a distance somewhat greater thanthe width of the platform which the elevator is intended to operate; Oneof the side members 2 is wider than the other, and supports a the drivemechanism; as explained at a later part of the" specification.

Corner posts 3'extend upwardly from each end of each side channel, and atop frame, comprised of the side elements 4, 4, one for each side, andthe crosswise elements 5, 5, one for each end is carried upon the cornerposts3 at their upper terminals. It is preferable to construct thesuperstructure which is carried upon the side channels 2 of tubularsteel or of pipe sections appropriately welded together.

Each of the corner posts 3 carries an eye 6 for the reception-of. slinghooks from a crane. these eyes, the elevator may be raised and loweredinto po-sitio'nto a'nd from a barge, using the mounted upon the wider"of the side members 2, inwardly'from the corner posts 3 at each end ofit. The posts I comprise pipe sections connected at their upper ends tothe top side memwhich is indicated generally at 9.

her 4 and terminating at their lower ends in U- shaped forks 8. Theforksare employed for the purpose of straddling and making accessible theendwise portions of the elevator drive mechanism Drive mechanism Thedrivefor, the apparatusv mounted upon .gthewiderof theside members2.and,comprises on the studs 1.

a motor unit Ill which, at one end, is equipped with a power brake IIfor stopping the rotation of the motor after it is deenergized. Thelatter unit extends through the aperture in the fork 8 at one end of theframe. Motor I0, through a coupling l2, drives a shaft l3 which rotateswithin a housing 54 where it carries a 45 helical gear l5 (Figure 11).An anti-friction bearing I6 is provided at one end of the housing forsupporting the shaft [3, while a thrust bearing I1 is mounted at theother end. The shaft I3 is threaded to receive lock nuts 18 and IQ forholding the bearing elements and helical gear in assembly, and washer 20is threadedly carried by the shaft intermediate the helical gear and theanti-friction bearing. All of the nuts and washers are provided withlock screws 2| for locking them in position.

Caps 22 and 23 are bolted to the end of the housing I4, the formerextending telescopically within the housing to support the anti-frictionbearing and the latter being provided with a packing gland 24 throughwhich the shaft l3 extends. The housing is filled with lubricant and isprovided with a plugged'drain outlet 25.

Helical gear l5 meshes with another 45 helical gear 26 which is carriedupon a stub shaft 21 within a housing 28. The stub shaft is at rightangles to the shaft I3 and carries a worm 30 which drives a worm wheel3|. The housings l4 and 28 are connected to one another as by welding,and apertures are provided in each through which the helical gears I5and 26 extend in rotative engagement with one another.

Stub shaft 21, like the main shaft 13, is journalled at one end inananti-friction bearing 32 and at the other in a thrust bearing 33. Thisshaft likewise contains lock nuts 34 and 35 and a Washer 36 similar tolock nuts [8 and I9'and washer 20, as previously described. The housing28 carries end caps 31 and 38, the former extending telescopicallywithin the housing to support the journal 21, and the latter beingprovided with a similar annular flange to abut the thrust bearingassembly and hold it against a seat turned within the housing. Helicalgears l5 and 26 and the worm wheel 30 are keyed to the shafts in theusual manner.

The worm wheel 3! rotates in a plane parallel to the axis of shaft 2'l,and is housed within a casing comprised of upper and lower members 40and 4| bolted together as at 42. The casing is Welded to the casing 28,as at 43, and the upper portion of. it includes a lubricant inlet 44.The casings 40, 28 and I4 all are in communication with one another andlubricant introduced at 44 may be removed at the pluggedopening 25. Theworm wheel casing comprises journals 45 for supporting a shaft 46 towhich the worm wheel 31 is keyed. v

Shaft 46 operates cable drums 4l4'!; these are installed intermediatethe posts 3 and l at each end of the frame. However, the ends of theshaft 46 also are journalled in blocks 48 mounted to the corner posts 3,and in journals 49 carried From the foregoing description of the drivemechanism it will be seen that the shaft [3 of the drive motor H) isparallel with the shaft of the cable sheaves. This arrangement isparticularly desirable for compacting the structure in order that it besuificiently narrow to be lowered through barge hatchways.

Drive control mechanism Shaft 46 carries an elongated sleeve 50 whichextends intermediate-the journal 45 at the 'hous-- ing ll-42;anduthejournal 49atthe one end of the. frame. The internal diameter ofthe sleeve is greater 5 than the diameter of the H shaft i and i 5bushings .5l-5l-are.disposed. intermediate the shaft andthe sleeve at.points vadiacentthe journals.- The sleeve 50-is locked.to rotatewith theshaft by. means ofthaset screw 52,? and" the exterior surface thereofcontains a spiralgroove 53- i which. constitutes. a :drive for the.=contro1ler dog indicated generally at 54....

Adjacent theshaft 46,. and extending .paralle'l with it, is a.pair .ofstationary shafts 55* These are, supported .uponopposite sidesoftheposts 1-1 at their ends respectively, for instance,- in bracketsextendingtfrom the -journal.49.iand the housing member 41:, and "arepositioned slightly above -the sleeve 50. for. slidably supportingtherea between the control dog 54.1. The .latter .unit'is *comprisedofslide bearings 56-.-.56..boredfor.slidable engagement :with the. shafts55-1-55 respem tively... A plateg5'l. is connected across thebearing.members to carryaestud 58. which, in turn, is. boredtoreceivea pin .59having atits lower end. a, finger filltadapted :to' engage the spiralgroove53 in. the sleeve.50.: The stud 58. contains a counter. bore 6 I.for receiving. a spring. 62 surroundingthe pin 58,:and the pin, inturn,.con-. tains, a keeper flange. 63...with. which thelower 'edgeofthe spring is in abutment. Thelspringlis.

of; the compression .typetand tends tokeepthe finger fiflzwithin thespiral groove ofthe. drive sleeve.

, However, a .lift .pin 64 extends transversely 'through the pin 59 andnormally resides within a slot'cut in the stud 58 2 but the stud 58 alsois provided with a raised support portion adapted toreceive the pin64.when the finger 59 is lifted and rotated through a quarter turn...This arrangement permits the. finger to .be liftedand kept out ofengagement. with the groove in the sleeve in order that the controlassembly 54 .be decommissioned orslid back .and forth, atwill, upon theguide rods 55. i

Dog members 65.65 extend. from thestud 53. imopposite directionsparallel .with sleeve 5!].

One of the shafts 55 contains upper .andlower limit switches 66 and 61respectively: Theseare I in electrical interconnection with appropriate.-re-

c=laysforpcontrollingthe source of energy ;to :the

drive motor lflgand the powerbrake IL, The

limit switches, are adjustably mounted upon the shaft and are free ,tobe. slid longitudinally of.

it by looseningthelock screws 68. 551

shafts 59, .which'support armsHL-IO, each of whichat its lower extremitycontains an. abutment wheel ll- The abutmentwheels. are positioned inthepath of movement of, the dog memerated byone or the other of dogs 65when the platform of the elevator is at an upper or lower 7517. S ppingposition.

The limitiswitches are provided with operating 7 side flanges.

Cable rigging The cable drums 4! are provided with end flanges "l2 andthe surface of each .drum is grooved to accommodate two cables. Adjacentthe .cabledrums and above them ,jack shafts 13-13 are provided, eachforsupporting two cablesheaves l5 and 16. On the other side of thesuperstructurejack shafts 'l4l4 are provided with sheaves 1lTl. All. ofthe sheaves, are positioned so that the innermost points upon theirperipheries extend inwardly of the flanges; of the channel members 2upon which the superstructure is carried. Each of the jack shafts l3 and14 issupported stationarilybetween a 15,} pair of buttress plates 18-48,One of the plates of each pair extends inwardly from corner post 3 ofthe superstructure and the other from the adjacent vertical support 1,as shown in Figure 8. The buttress plates preferably are provided withbosses l9 welded thereon, and the ,jack shafts are carried by thebosses. All sheaves are free to rotate about the shafts and also move.longitudinally on them.

At the side of the, superstructure opposite the. 5,; drive mechanism andbeneath the sheaves TI idler sheaves 80-.80are provided, as shown inFigure 3.- These are rotatably and slidably mounted upon jack shafts8l8l, at each end of the frame, the jack shafts being mounted'ine 3m,termediate the buttress plates as, previously described.

Each cable drum operates twosets of cables, 0 one set 82--82 for thenear side, of the platform, and the other set 83783. for the. far sideof the 35;; platform. The cables 82 pass. fromthe drums, up and over thesheaves 16,.then down pastthe drive mechanism; The cables83. of theother set pass upwardly over the sheaves l5 respectively, across thetopof the superstructureand 40 over the sheaves TI. The cables passaround. these sheaves and. are projected forwardly .over the idlersheaves 811.150 as to extend downwardly through the frame at theopposite side of the apparatus.

The cables 82 and 83 .supporttheplatform which is indicated generally at84.. This comprises an appropriate rigid plate 85 with sidefianges.'8585 provided thereon at the opposite edges. The width of theplatform is such that it may passfreely intermediate the sidechannels 2of the frame, while the length of it is determined in accordance withthe apertures or hatches through which it is intended tooperate.

The cables 82 and 83 are connected to the 55 platformat its cornersthrough snubberswhich are indicated generally at 8i the construction ofthese is illustrated in Figure 9. Each snubber comprises a tubularmember 88, slotted at its lower end as at 89 to provide a clevisconnection with the side flange 86 of the platform with the pivot pins.890; connecting the clevises to the 1 Housing 88 of the snubber isclosed at its upper end to, contain a bore-of reduced diameter throughwhich a :plunger 90 passes, for instance, the housing, as illustrated inFigure 9, may be made from a piece of pipe with the upper end swagedinwardly to provide it witha shoulder 9! against which a sleeve 92 isdisposed. Compression spring 93 extends about the plunger intermediatethe sleeve, and a flange 94 is provided at the lower end of the plunger.The lower ends of the cable are provided with connectors 95 and theseare-pinned 7 sa as at 96 to the parts of the plungers extending abovethe housings.

'The snubbers are adapted particularly to prevent abrupt shocks in thecable or drive mech- .1 anism. When the platform, being lowered,

comes into contact with the floor of the barge, the compression springs93 take up the shock and at the same time keep the cable in tautcondition. This feature is of considerable practical importance in viewof the fact that the stopping position of the platform varies from timeto time as the barge tends to list when it i being loaded or. unloaded.

I Brow plates for platform At the ends of the channel members 2, blocks91 are provided for pivotally supporting brackets 98. These bracketsextend beyond the ends of the-platform and downwardly to carry brow"iplates 99"which extend across the elevator frame.

The rearward edges'of the brow plates are provided with plates I00,hinged thereto as at "H. The hinged plates extend inwardly toward theelevator platform for engagement with sills I02 2-.which are fastened tothe lower face thereof at each of its crosswise edges.

During the lifting of the platform, the sills I02 engage the hingeplates I 90 and the gap between the edges of the platform and the edgesof the aperture of the deck, through which it is operating, is thusbridged. This feature is of considerable practical importance forseveral reasons; in the firstplace the deck or roof areaway for theplatform varies considerably from barge to barge, and there mustnecessarily be considerable clearance for the platform. On the otherhand, very careful locating of the elevator over the opening is tediousand time consuming. The arrangement disclosed makes it possible to usebut reasonable care in locating the elevator above frame and preventingthe channel members from moving away' from one another during extendedusage of the apparatus. Utilizing structural members at the top of thestructure sufficiently heavy to prevent separation of the channel memberis avoided.

The latches I03 extend from the corner post 3 of the superstructure forholding the brow plates in raised position when the elevator is beingmoved into or out of position.

Ordinarily, the elevator apparatus is supported upon'oasters I04 whichare: carried pivotally, as at I05, beneath the channel members 2. Withthebrow plates in raised position, these casters.

enable the elevator to be rolled about at will ,.until it is broughtinto proper position.

However, during the usage of the elevator, the frame is supportedagainst movement upon jacks Which are illustrated in Figure 4. Thesejacks are located adjacent the casters I94 and are -raised and loweredthrough a toggle apparatus as follows: ,Each jack comprises a footportion I0'I carried upon ashaft I08. The shaft extends through a sleeveI09 which is welded to the channel 2, a supplementary channel III] beingused to rigidify the connection of the sleeve with the channel member.The upper portion of the member I08 is'connected pivotally, as at III,to a toggle link H2, and this link, in turn, is connected to anothertoggle link H3 which is pivotally supported from the fork portion 8 ofsupport l. The link I I 3 is bored for the reception of a lifting bar H4in order that the toggle .be thrown to press .the foot against thefloor, and thereby raise the elevator from its caster wheels. When thetoggle links are in alignment with one another, the frame is in theelevated position and is supported upon the feet I01. In this positionthe elevator is mounted stationarily. Figure 4 illustrates the feet inthe process of being operated.

At the inner edges of the side channels 2, the guide members H5 areprovided, one pairfor each side. These members are mounted pivotallyupon the flanges of the channels, as at H6, and preferably are made asflanged bars which extend inwardly toward one another from the edges ofthe channels and then downwardly substantially beyond the casters, forinstance, a distance approximately half-way to the lowermost position ofthe platform. The lower portions of the guide members are bent outwardlyto receive therebetween the flanges 86 of the platform. These barstherefore guide the platform during its movement and prevent it fromswaying as it is lowered and raised. When the elevator is beingdecommissioned the guide brackets are swung inwardly to rest upon theplatform so that they are out of the way while the apparatus is beinghandled.

Having described my invention, I claim:

1. A portable elevator comprising a wheeled carriage delineating aplatform passageway, a platform positioned within the passageway, meansfor hoisting the platform supported from the carriage, and guide meansextensible from the carriage for guiding the platform when it is inpositions below the passageway.

2. A portable elevator comprising a wheeled carriage delineating aplatform passageway; a

platform positioned within the passageway, electric drive means forhoisting the platform supported from the carriage, guide meansextensible from the carriage for guiding the platform when it is inpositions belo-w the'passageway, and electric controller means forcontrolling the hoisting mechanism when the platform is in predeterminedpositions relative to the carriage.

3. A portable elevator which is to be used in loading or unloadingbarges, comprising a chassis delineating a passageway, wheels carried bythe chassis beyond the. passageway, 'a platform adapted to be movedthrough the passageway in the chassis, means for moving the platform,and guide means extensible from the chassis for guiding the platformwhen it is in positions below the'wheels of the chassis.

4. A portable elevator comprising a wheeled carriage delineating aplatform passageway, a platform positioned within the passageway,electric drive means for hoisting the platform supported from thecarriage, guide means extensible from the carriage for guiding theplatform when it is in positions below the passageway, and elec-- triccontroller means for controlling the hoisting mechanism when theplatform is in predetermined positions relative to the carriage,including a threaded shaft rotatable in synchronism with said electricdrive means, dog means movable sitioned in the path of movement of saiddog means and actuab-le thereby for controlling said electric drive.

5. A portable elevator comprising a frame having supporting wheelstherefor and adapted to be positioned over an aperture in a barge deck,a platform movable within the frame and below it, a hoisting mechanismcarried by the frame for moving the platform, and guide means normallycollapsed within the frame when the elevator is not in usage, butarranged to be extended below the frame for guiding the platform whenthe elevator m in usage.

6. A portable elevator which comprises platform members which extend inspaced parallel relationship, interconnected members supported from saidplatform members and extending upwardly therefrom to form a rigid framewhich. is of inverted U shape in cross section, wheel members formovably supporting said frame, sheave members supported at the upperpart of the frame and at opposite ends thereof, a platform, cablesupport members therefor located within the frame with the cablespassing over the sheaves, drive means for operating said cables, locatedat one side of the frame and comprising a motor and cable drums inspaced relationship with one another, but extending longitudinally ofthe frame, and an assembly for ro-tatably interconnecting said motor andsaid drums, including helical gears mounted on a shaft extending in adirection transversely of said frame.

'7. A portable elevator for purposes of the type described, whichcomprises interconnected members forming supports of inverted U-shapewhich are spaced apart from one another, means interconnecting saidinverted U-shaped members, and therewith forming a frame, wheel meansfor movably supporting said frame, a brow plate extending transverselyacross an end of said frame at a lower part thereof, and means hingedlyconnecting said brow with said frame, the brow plate serving as anentranceway to said platform, and the brow plate serving to interconnectthe lower terminals of the members forming the said frame.

8. An elevator for purposes of the type described, comprising a frameincluding corner posts, means respectively interconnecting the cornerposts at their upper terminals, a platform movably located within saidcorner posts, and means for interconnecting the lower terminals of thecorner posts at opposite ends of the platform, comprising brow platemembers and supporting means therefor hingedly mounted upon the lowerterminals of the corner posts.

9. An elevator device of the type described, comprising a portableframe, a platform movable within said frame, wheels for transporting theframe, and means including toggle members and longitudinal supportmembers, with the toggles interconnecting the frame and thelongitudinally movable support members, the support members beingadapted to be actuated by said toggles for stationarily supporting theframe of the elevator.

10. A portable elevator comprising corner post members interconnected attheir upper extremities to form a frame, means respectively connectinglower portions of the corner posts at the opposite sides of the framewith one of said means providing a platform support, a drive motormounted substantially longitudinally of said frame upon said platform,support hoisting drum means having an axis of rotation extending in thedirection of the axis of the drive motor and ratatably supported uponsaid frame adjacent the drive motor, means for interconnecting saiddrive motor and said hoisting drum, including helical gear members andjack shaft (extending in a direction transverse the frame) forsupporting one of said gear members, an elevator platform operablethrough said frame, and means for operating said platform from saidhoisting drum means.

11. A portable elevator of the type described, which comprises cornerpost elements, means interconnecting the corner posts to one another attheir upper extremities to form a frame, a platform supported from onepair of corner posts longitudinally of the frame, a motor supported onthe platform and having a drive shaft extending longitudinally of theframe, a jack shaft extending transversely of the frame, helical gearmembers in meshing relationship mounted respectively upon said jackshaft and drive shaft, a shaft having cable drums and worm wheel meansinterconnecting said shaft having cable drums and said jack shaft withthe shaft supporting the cable drum means extending longitudinally ofthe elevator frame, an elevator platform which is movable within saidframe sheaves supported by said frame at an upper portion of it andcable means operated by said cable drums and extending over said sheavesinto connection with said platform.

12. A portable elevator for purposes of the type described, comprisingan elevator platform, a frame through which said platform is operable, amotor supported upon said frame at one side of said platform, cable drummeans, cables actuated by said drum means for operating said elevatorplatform, gear means for operating said cable drum means from saidmotor, a shaft rotatable with said cable drum means and providing aspiral groove upon its surface, a control dog movable longitudinally ofsaid shaft and having a member engaging said groove, and electricalswitches for controlling said motor, said switches being positioned inspaced relationship in the path of movement of said control dog andadapted to be operated by said control dog for controlling said'motorwhen said platform reaches predetermined portions.

HARRY C. ELLIOTT.

